1. Field of the Invention
This invention relates to an image memory apparatus and more particularly to an image memory apparatus in which, for example, the length and width of a picture can be exchanged with each other.
2. Related Background Art
Conventionally, an image memory apparatus is known which has a so-called dual port function of writing and reading image information as well as rewriting image data from an external circuit.
In the conventional memory apparatus, however, the sequence of writing addresses and the sequence of reading addresses are predetermined, so that when reading is performed in a sequence different from that of writing as in the case where the length and breadth of a picture are changed, writing and reading of image information from an external circuit can be impossible.